Piezoresistive Reponse of Aligned Carbon Nanotube Arrays for Flow Sensing Applications

We investigate the electromechanical sensing capabilities of aligned carbon nanotube (CNT) arrays as a means for a lightweight and simple electromechanical transduction element. CNT array heights of 25 and 350 μm are examined using a modified dynamic mechanical analyzer (DMA) to impart multiple strain-based test configurations while simultaneously measuring electrical resistance. Observed gauge factors range from 12.5 for the 25μm array to greater than 190 for the 350 μm array, with a peak sensitivity of 13,750 ohms/gram force achieved for the 350 μm array. The electromechanical response observed was independent of the examined frequency range, suggesting high fidelity sensory capabilities. Results of this study serve as a preliminary proof of concept for using CNT arrays as a transduction mechanism for a proposed artificial hair sensor for small air vehicles.